After a repeat blood test, PET scan, and needle biopsy, he was diagnosed with Hodgkin’s lymphoma. “I cried,” said the retired real estate agent. “Just two tears and I thought, ‘Okay, now what do we do?’ The Canby Oregon resident had volunteered to have a blood test marked as a new frontier in cancer screening for healthy people. Looks for cancer by checking for DNA fragments that are discarded by tumor cells. Such blood tests, called liquid biopsies, are already being used in cancer patients to adjust their treatment and check if the tumors recur. Now, a company is promoting its blood test in people without signs of cancer as a way to detect tumors in the pancreas, ovaries and other places that do not have a recommended screening method. It is an open question whether such blood tests for cancer – if added to standard care – could improve American health or help achieve the White House’s goal of halving cancer mortality over the next 25 years. With advances in DNA sequencing and data science enabling blood tests, California-based Grail and other companies are fighting for their commercialization. And U.S. government researchers are planning a major experiment – likely to take seven years and with 200,000 participants – to see if blood tests can deliver on the promise that we will catch more cancers sooner and save lives. “It sounds great, but we do not have enough information,” said Dr. Lori Minassian of the National Cancer Institute, which is involved in planning the research. “We have no definitive evidence that they will reduce the risk of dying from cancer.” Grail is well ahead of other companies with 2,000 doctors willing to prescribe the $ 949 test. Most insurance programs do not cover the cost. The tests are marketed without the approval of medical teams or recommendation from US health authorities. No inspection by the Food and Drug Administration is required for this type of test. The story goes on “For a drug, the FDA requires that there be a high probability that the benefits will not only be proven, but also outweigh the harms. That’s not true of devices like blood tests, “said Dr. Barry Kramer of the Lisa Schwartz Foundation for Truth in Medicine. Grail plans to seek FDA approval, but is pushing for testing as it submits data to the agency. The history of cancer screening has taught attention. In 2004, Japan halted mass screening of infants for childhood cancer after studies found that it did not save lives. Last year, a 16-year study of 200,000 women in the United Kingdom found that regular screening for ovarian cancer made no difference to deaths. Cases like these have revealed some surprises: Screening detects some cancers that do not need treatment. The other side; Many dangerous cancers grow so fast that they go out of control and prove to be deadly anyway. And screening can do more harm than good. Stress from false positives. Unnecessary cost. And serious side effects from cancer care: PSA tests for men can lead to treatment complications such as incontinence or impotence, even when some slow-growing prostate cancers would never have caused problems. The data are stronger for screening tests for cancers of the breast, cervix and colon. For some smokers, screening for lung cancer is recommended. Recommended tests – mammogram, PAP test, colonoscopy – look for one cancer at a time. New blood tests look for many cancers at once. That’s an advantage, according to Dr. Joshua Ofman, Grail executive. “We are screening for four or five cancers in this country, but (many) cancer deaths are from cancers we are not looking for at all,” Ofman said. Dr. Tomasz Beer of the University of Oregon University of Oregon Health & Science led the study, which was funded by Joyce Ares’s company in 2020. After a miserable winter of chemotherapy and radiation, doctors said the treatment was successful. Her case is not an extreme one, “but it is the expected ideal result and not everyone will have it,” Beer said. While there were other early cancers identified among study participants, some had less clear experiences. For some, blood tests have led to scans that never detected a cancer, which could mean the result was false positive or it could mean that there is a mysterious cancer that will appear later. For others, blood tests have identified cancer that has been shown to be advanced and aggressive, Beer said. An older participant with a bad case refused treatment. Grail continues to update its test as it learns from these studies and funds a trial with the British National Health Service on 140,000 people to see if a blood test can reduce the number of cancers that have been diagnosed in the late stages. Although Mars feels lucky, it is impossible to know if her test added healthy years to her life or made no real difference, said Kramer, a former director of the Cancer Prevention Department at the National Cancer Institute. “I sincerely hope Joyce benefited from this test,” Kramer said when told of her experience. “But, unfortunately, we do not know, on an individual Joyce level, if this is the case.” Cancer treatments can have long-term side effects, he said, “and we do not know how quickly the tumor would have grown.” Treatment for Hodgkin’s lymphoma is so effective that delaying treatment until the symptoms are felt can have the same happy effect. At present, health experts stress that the Grail blood test is not a diagnosis of cancer. a positive result triggers further scans and biopsies. “This is a path to diagnostic testing that has never been tried before,” Kramer said. “Our ultimate destination is a test that has a net benefit. If we do not do it carefully, we will get off track.”
The Associated Press Department of Health and Science receives support from the Department of Education Sciences of the Howard Hughes Medical Institute. The AP is solely responsible for all content. Carla K. Johnson, The Associated Press
